All in Praying in Full

When we are in need of something miraculous to occur, or we want something that is so far above us that we believe it is just too great, or much, to ask for, do we temper our prayers, and ask God for what we believe is actually doable? Do we ask God for a lesser thing because we think it is possible for Him, and that He might be capable of providing it? Perhaps we believe we are unworthy, or that our true desire is presumptuous in nature, and so we weigh our prayer requests against who we think He is, and how much we believe He loves us, but this is only an indication of our lesser faith, and not how God wants us to come to Him, or ask of Him.